Deborah Cox (born July 13, 1973 in Toronto, Ontario) is a Canadian R&B/pop singer, whose 1998 song "Nobody's Supposed to be Here" was the longest-running number one single in the history of Billboard magazine's R&B charts. Cox has achieved nine number-one hits on Billboard's Hot Dance Music/Club Play Chart.

Cox entered the music industry as a backup vocalist for Céline Dion, and after signing to Arista Records, released her self-titled debut album in 1995. The album made her a rising star, and set the stage for 1998's One Wish. The first single from that album, "Nobody's Supposed to be Here", spent fourteen weeks at number one on Billboard's Hot R&B/Hip-Hop Singles & Tracks chart. While Cox began her career strictly as an R&B artist, she is now more well-known for her work in the dance/techno genre.

On February 17, 2004, Cox made her Broadway debut in the Elton John-Tim Rice musical Aida.